Acording to http://www.geocities.com/SunsetStrip...761/tips1.html

logo.sys -> Starup Screen
logow.sys -> Prior to shutdown
logos.sys -> final shutdown (Now safe to turn off computer)

I thought I might add, A shell launcher called ShellON from http://www.indexo.pionexnet.co.uk/su...dldshellon.htm has a built in start screen chooser, it lets you choose a difernt set of startup and shutdown screens for each of your shells. A nice shell called Cloud 9ine can be found at http://www.cloud9ine.com/main.asp